[SOLVED] grounding question for inverter circuit

grounding question(not yet solved sorry)

Should our inverter driver(mcu, opamps,ir2112) have the same ground with our dc link(rail which is almost 450V)?

our circuit is like what is in section 6(inverter section) of this pdf

**broken link removed**


now we don't know if the our DRIVER's ground should be connected to the ground of that dc link. thanks

As far as you refer to IR2112, these devices clearly require the control voltage ground VS and the low side driver ground COM to share the same voltage node. The seperate connections allow a limited voltage difference without affecting the circuit operation. There are several application notes dealing with this topic, e.g DT 97-3 or AN-978. In any case, the driver power supply common needs to be shorted to the negative bus terminal somehow.

You should consider, that the domain of IR211x driver ICs is low and medium power applications. They aren't well suited for the level of interferences observed in high power application and don't provide sufficient gate current for it. Furthermore, the valuable power semiconductors deserve a sophisticated protection concept not available with these simple devices.